Core drill



www 27, M270 CORE DRILL Filed NOV. 5, 1923i Patented Dec. .27, .1927'.

STATES PATENT OFFICE.

JOSEPH Sy. MITCHELL, OF CI-IIAG, ILLINOIS, ASSIGNR T0 SULLIVAN MACHINERYCOMPANY, A. CORPORATIGN OF MASSACHUSETTS.

CORE DRILL.

Application filed November 5, 1923.

My invention relates to core drills.

It has :tor its object to provide an improved core barrel and moreparticularly an improved core barrel oi the type adaptedto oil or gaswell drilling and wherein as a result oi' the large and heavy cores.dealt i with and the use oi mud tiuid, a barrel of Oft increasedstrength and adapted to provide passage means ot adequate size, isrequired. More particularly my invention has for its objects to providean improved core lifter shell 'adapted to use in such a barrel.

In the accompanying drawings I have shown for purposes of illustrationone form and a modification thereof which my invention may assume inpractice.

In these drawings,-

Fig. 1 is a partial vertical section showing my invention embodied in a,barrel.

Fig. 2 is a transverse section on line 2-2 of Fig. 1.

Fig. 3 is a transverse section on line 3 3 of Fig. 1.

Fig 4 is a transverse section on line 4-4 of Fig. 1.

Fig. 5 is a fragmentary view similar to Fig. el, illustrating a slightlymodified form construction.

In this illustrative construction I have shown a barrel oi 'the generalconstruction described and claimed in my copending application Ser. No.579,038, filed Aug. 1, 1922,

comprising an internally and externally flut-ed bit 1 and a similarguide 2 above the bit, these elements being connected by a core liftershell 3 of improved construction, hereinafter described and carryingtherein a usual core lifter 4, and all being adapted to deliver mudfluid to the bottom of the hole.

Referring more particularly to m 1mproved construction `it will bev notethat the shell 3 is threaded to external threads on reduced oppositeends of the members 1 and 2, by internal threads on and extending asubstantial distance inward from the o posite ends of the member 3.Further, t e outside diameter of the intermediate portion of the shellis uniform and slightly less than the outside diameter of both the bitand the guide, though slightly greater than circles substantiallyincluding the bottoms of the Hates in those members, while reducedp0rtions 5 and 6 at opposite ends of the member 3 are provided,respectively adjacent the inlet ends of the tiutes'in the guide 2 andthe Serial No. 672,796.

outlet ends of the external iutes on the bit 1. More particularly, itwill be noted that the area between the 'intermediate portion and thewalls of the hole is substantially the same as the sum ofthe areas ofthe tintes in the bit or guide. Moreover, the reduced portion 5 is ot' aslightly larger outside diameter than a circle substantially includingthe bottoms ot the grooves in the member 2 and is connected to theintermediate'portion of the member 3 by a sloping, and preferablyconical, portion 7. It will further be noted that the same generalconstruction has been used in connection with the reduced portion 6which is of substantially the same outside diameter as a like circlesubstantially in cluding the bott-oms of the external grooves in the bit1 and is connected t the intermediate portion of the memberi3 by asloping or conical portion 8. As shown in Fig. 5 the core lifter shell 3may be externally luted, as at 9, throughout the lengthof theintermediate externally enlarged portion to provide a slight additionalflow of fluid to pass the shell without substantially weakening theshell.

As a result of my improved construction, y

the proper proportioning of this member 3` with its intermediate outsidediameter providing a liow area adapted to 'cooperate with the flow areasin the bit and guide, and by reason of the reduced portions at the endsof this intermediate portion, the ldesired fluid ow between the bit andthe guide is maintained. Further, as `a result of this construction, itwill be noted that it is possible to obtain the desired strength andfluid iiow without any necessity` for uting this particular member andthereby necessarily weakening the same, `although obviousl should aslight additional flow be de sire the construction of the member 3 willpermit of a certain amount of tluting, as inicated in Fig. 5, withoutsubstantial weakenin 'IVhile I have in this application specicallydescribed one form and a modification thereof which my invention ma as,-eume in practice, it will be understan that eter than t this form andmodification of the same are shown for purposes of illustration and thatthe invention may be modiiied and embodied in various other formsWithout departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is: 1. In acore barrel comprising guide and bit portions, a core lifter shellconnecting the same and having an intermediate portion of greaterexternal diameter than its ends, said intermediate portion being ofsmaller external diameter rthan said guide and bit portions.

2. In a core barrel comprising bit and guide portionshaving externalfluid pas,- sages t erein, a core lifter shell connecting the same andhaving an intermediate p0rtion of greater external diameter than itsends, said intermediate portion being of smaller external diameter thansaid bit and guide portions land so roportioned as to permit a'free iow'of fluid between said bit and uide portions. 3. n a core barrelcomprising externally grooved bit and guide portions, a core liftershell connecting the` same and having an intermediate portion of greaterexternal diameter than the portions of the same ad- 'acentthe bottoms ofthe grooves in said it and guide portions, said' intermediate portionbeingo smaller external diameter than said bit and guide portions.

4. In a core barrel comprising externally grooved bit and guideportions, a core lifter shell 'connecting the same and having anintermediate portion of greater external diame portions of the sameadjacent the bottomsvof the grooves in said members,

Y said 'smaller portions eachy being of substantially-the diameter ofthe bottoms of the grooves in its adjacent member.

5. Ina core barrel comprisingexternally' grooved lbit and guideportions, a core lifter shell connecting the saine and having an intermediate vportion of greater external diameter than the portions ofthe same adjacent the bottoms of the grooves in said members, said lastmentioned portions each being of substantially the diameter of thebottoms of the grooves in its adjacent member and the body portion ofsaid shell being ot smaller external diameter .than the bit.

6. A core barrel comprising an externally tinted bit, an externallytinted guide, and an untluted intermediate core lifter shell of greaterexternal diameter intermediate it-s ends threaded thereto by threadedportions extending into said intermediate ortion and foimin a unit ofsubstantial y uniform strengti throughout its length and formingthroughout its length an external passage of an area substantially equalto the fluid flow area along said bit and guide.

j 7. In a core barrel comprising externally grooved bit and guideportions, a core lifter shell Connecting the same and having anintermediate portion of greater external diameter than-the portions ofthe same adjacent the bottom of the grooves in said members and soproportioned as to present a flow area substantially the same as thearea of the groove in said grooved ortions, said smaller portions eachbeing o substantially the diameter of the bottom of the grooves in itsadjacent member.

8. In a core barrel comprising externally grooved bit and guide ortions.a core lifter shell threaded thereto )y threaded portions extending intosaid shell, said shell having anv intermediate portion of greaterexternal diameter than the portions of the same adjacent the bottoms ofthe grooves in said it and guide portions, said smaller poi'- tions eachbeing of substantially the diameter of the bottoms of the grooves in itsadjacent member.

In testimony whereof I affix my signature.

' JOSEPH S. MITCHELL.

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